SeaLevel SeaLINK+4 User manual

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© Sealevel Systems, Inc. 2403 Manual | SL9102 6/2021
SeaLINK+4
User Manual | 2403

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© Sealevel Systems, Inc. 2403 Manual | SL9102 6/2021
Contents
CONTENTS...........................................................................................................................................................2
BEFORE YOU GET STARTED ...............................................................................................................................3
PRODUCT DESCRIPTION.....................................................................................................................................4
ELECTRICAL SPECIFICATIONS...........................................................................................................................9
TECHNICAL SPECIFICATIONS..........................................................................................................................11
HARDWARE CONFIGURATION..........................................................................................................................12
INSTALLATION ..................................................................................................................................................16
APPENDIX A – TROUBLESHOOTING................................................................................................................24
APPENDIX B – HANDLING INSTRUCTIONS.....................................................................................................28
APPENDIX C – ELECTRICAL INTERFACE ........................................................................................................29
APPENDIX D – ASYNCHRONOUS COMMUNICATIONS ..................................................................................30
APPENDIX E – COMPLIANCE NOTICES...........................................................................................................31
APPENDIX F – HOW TO GET ASSISTANCE .....................................................................................................33
WARRANTY ........................................................................................................................................................34

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© Sealevel Systems, Inc. 2403 Manual | SL9102 6/2021
Before You Get Started
What’s Included
The 2403 is shipped with the following items. If any of these items are missing or damaged, please contact
Sealevel for replacement.
•2403 – USB to RS-232/422/485 4-Port Serial Interface Adapter
•CA179 – USB Device Cable for Connecting to Upstream Host/Hub
Advisory Conventions
Warning
The highest level of importance used to stress a condition where damage could result to the
product, or the user could suffer serious injury.
Important
The middle level of importance used to highlight information that might not seem obvious or a
situation that could cause the product to fail.
Note
The lowest level of importance used to provide background information, additional tips, or other
non-critical facts that will not affect the use of the product.

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Product Description
The SeaLINK® 2403 USB serial I/O adapter equips the PC with four RS-232, RS-422, or RS-485
asynchronous serial ports for USB connectivity to legacy or non-USB compliant devices. The advantage of
this product over more traditional approaches is that it does not require opening the computer case, nor
does it require resources such as I/O ports or IRQ’s. It does require a system that supports USB both in
terms of hardware and operating system.
Sealevel SeaCOM USB software drivers and utilities make installation and operation easy using Microsoft
Windows and Linux operating systems. After installing the software, simply connect the 2403 serial
interface adapter to your USB port. The device and serial ports are immediately recognized as standard
COM ports by the host system enabling compatibility with legacy software. Now your non-USB peripherals
can have the same connection simplicity and ease of use as USB aware peripherals.
Features
•Compliant with RoHS and WEEE directives
•Each port individually configurable for RS-232, RS-422, or RS-485
•High-speed UART with 128-byte Tx FIFO and 384-byte Rx FIFO
•Data rates from 300 bps to 921.6 Kbps
•Automatic RS-485 enable/disable
•Serial and USB activity LEDs
•Hot-swappable
•Powered by USB connection
•Sealevel SeaCOM software supports Microsoft Windows and Linux operating systems
•DB9M connectors
•Includes 6’ USB device cable (Item# CA179)
.

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Optional Items
Depending upon your application, you are likely to find one or more of the following items useful. All items
can be purchased from our website (www.sealevel.com)by calling our sales team at [phone].
Cables
Terminal Block - DB9 Female to 5 Screw Terminals (RS-422/485) (Part# TB34)
The TB34 terminal block adapter offers a simple solution for
connecting RS-422 and RS-485 field wiring to a serial port. The
terminal block is compatible with 2-wire and 4-wire RS-485
networks and matches the RS-422/485 pin-out on Sealevel
serial devices with DB9 male connectors. A pair of
thumbscrews secures the adapter to the serial port and
prevents accidental disconnection. The TB34 is compact and
allows multiple adapters to be used on multi-port serial devices,
such as Sealevel USB serial adapters, Ethernet serial servers
and other Sealevel serial devices with two or more ports.
DB9F to DB25M (RS-485) Extension Cable (Part# CA177)
The CA177 is a standard AT-style RS-232 modem cable with a
DB9F connector on one end and a DB25M connector on the
other. This cable is 72 inches in length.
DB9F to DB9M Extension Cable (Part# CA127)
The CA127 allows users to extend a DB9 cable up to six feet.
The connectors are pinned one-to-one,
so the cable is
compatible with any device or cable that has DB9 connectors.
DB9 Female to 9 Screw Terminal (Part# TB05)
The TB05 terminal block breaks out a DB9 connector to 9 screw
terminals to simplify field wiring of serial connections. It is ideal
for RS-422 and RS-485 networks, yet it will work with any DB9
serial connection, including RS-232. The TB05 includes holes
for board or panel mounting. The TB05 is designed to connect
directly to Sealevel DB9 serial cards or any cable with a DB9M
connector.

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OPTIONAL ITEMS,CONTINUED
Hubs
High Speed 4-Port USB 2.0 Hub with SeaLATCH USB Ports (Part# HUB4PH)
The hub is USB 2.0 compliant, providing a full 480M bps data
rate to the host, and is backwards compatible with USB 1.1 and
1.0 devices. The HUB4PH includes a wall-mount AC adapter
that supplies a full 500mA to each attached USB peripheral. The
power supply outputs 5VDC @ 2.
4A and has a locking DC
connector to prevent accidental removal of the power cable.
High Speed 7-Port USB 2.0 Hub (Part# HUB7P)
The HUB7P is USB 2.0 compliant, providing a full 480M bps data
rate to the host, and is backwards compatible with USB 1.1 and
1.0 devices. The powered hub includes a wall-
mount AC
adapter that supplies a full 500mA to each attached USB
peripheral. The power supply outputs 5VDC @ 4A and has a
locking DC connector to prevent accidental removal of the
power cable. The hub is housed in a rugged plastic enclosure
and status LEDs indicate external power, connection to the
host, and fault conditions.
Adapters and Converters
DB9F to RJ45 Modular Adapter (Item# RJ9S8)
The RJ9S8 is a DB9 female to RJ45 adapter. It can be
configured without tools and is an excellent choice for using
available infrastructure wiring.
DB9 Female to DB9 Male - Serial Surge Suppressor (Part# SS-DB9)
User configurable for use with male or female DB9 ports, the
SS-DB9 protects all 9 lines, plus D shell chassis. Convenient
DB9 input and output connects directly to the protected port,
obtaining a ground outlet from the computer chassis. Surge
suppression is handled with balanced arrays of high-speed
avalanche diodes that divert excess energies created by
electrostatic discharges, faulty wiring, or lightning away from
network interface connections.

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Product Family
Whether you require one serial port or 16, SeaLINK USB serial adapters will have you quickly communicating
with RS-232, RS-422, and RS-485 peripherals. Unlike traditional UART-based devices, SeaLINK USB
products use a state-machine architecture that reduces host processor overhead for faster, more reliable
communications. Sealevel's SeaCOM software drivers and utilities make installation and operation easy
using Microsoft Windows and Linux operating systems.
Part No. Description
2105R USB to 1-Port RS-232 DB9 Serial Interface Adapter
2106 USB to 1-Port RS-422 DB9 Serial Interface Adapter
2107 USB to 1-Port RS-485 DB9 Serial Interface Adapter
2113 USB to 1-Port RS-232, RS-422, RS-485 DB9 Serial Interface Adapter
2123 USB to 1-Port RS-232, RS-422, RS-485 (Software Configurable) DB9 Serial Interface Adapter
2101 USB to 1-Port RS-232 DB25 Serial Interface Adapter
2102 USB to 1-Port RS 422, RS-485, RS-530 DB25 Serial Interface Adapter
2103 USB to 1-Port Isolated RS-232 DB25 Serial Interface Adapter
2104 USB to 1-Port RS 422, RS-485, RS-530 DB25 Serial Interface Adapter
2108 Embedded USB to 1-Port RS-232 DB9 Serial Interface Adapter with Low Profile PC Bracket
2128 Embedded USB to 1-Port RS-232, RS-422, RS-485 (Software Configurable) DB9 Serial
Interface Adapter with PC Bracket
2201 USB to 2-Port RS-232 DB9 Serial Interface Adapter
2202 USB to 2-Port RS-422, RS-485 DB9 Serial Interface Adapter
2203 USB to 2-Port RS-232, RS-422, RS-485 DB9 Serial Interface Adapter
2208 Embedded USB to 2-Port RS-232 DB9 Serial Interface Adapter with Standard Size PC
Bracket
2213 USB to 2-Port Isolated RS-232, RS-422, RS-485 DB9 Serial Interface Adapter
2223 USB to 2-Port RS-232, RS-422, RS-485 (Software Configurable) DB9 Serial Interface Adapter
2228 Embedded USB to 2-Port RS-232, RS-422, RS-485 (Software Configurable) DB9 Serial
Interface Adapter with PC Bracket
2401 USB to 4-Port RS-232 DB9 Serial Interface Adapter
2402 USB to 4-Port RS-422, RS-485 DB9 Serial Interface Adapter
2403 USB to 4-Port RS-232, RS-422, RS-485 DB9 Serial Interface Adapter

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PRODUCT FAMILY,CONTINUED
Part No. Description
2404 USB to 4-Port RS-232 RJ45 Serial Interface Adapter
2407 USB to 4-Port RS-232, RS-485 RJ45 VersaCom Serial Interface Adapter
2423 USB to 4-Port RS-232, RS-422, RS-485 (Software Configurable) DB9 Serial Interface Adapter
2433 USB to 4-Port RS-232, RS-422, RS-485 (Software Configurable) DB9 Serial Interface Adapter
641U USB to RS-232 RJ45 Serial Interface Adapter
647U USB to RS-232, RS-485 RJ45 VersaCom Serial Interface Adapter
2801 USB to 8-Port RS-232 DB9 Serial Interface Adapter
2802 USB to 8-Port RS-422, RS-485 DB9 Serial Interface Adapter
2803 USB to 8-Port RS-232, RS-422, RS-485 DB9 Serial Interface Adapter
2804 USB to 8-Port RS-232 RJ45 Serial Interface Adapter
2807 USB to 8-Port RS-232, RS-485, RJ45 VersaCom Serial Interface Adapter
2823 USB to 8-Port RS-232, RS-422, RS-485 (Software Configurable) DB9 Serial Interface Adapter
2833 USB to 8-Port RS-232, RS-422, RS-485 DB9 Serial Interface Adapter
681U USB to RS-232 RJ45 Serial Interface Adapter
687U USB to RS-232, RS-485 RJ45 VersaCom Serial Interface Adapter
2161 USB to 16-Port RS-232 RJ45 Serial Interface Adapter
2167 USB to 16-Port RS-232, RS-485 RJ45 VersaCom Serial Interface Adapter

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© Sealevel Systems, Inc. 2403 Manual | SL9102 6/2021
Electrical Specifications
The 2403 utilizes four USB UARTs. These chips feature programmable baud rate, data format, 128-byte
dual-port TX buffer, and 384-byte dual-port RX buffer. The RS-232/422/485 transceiver supports data rates
from 300 baud up to 921.6 K baud for RS-422/485 and 460.8 K baud for RS-232. Refer to Appendix C for
cable length limitations.
Connector Pin Out
RS-232 (DB9 Male)
Pin # Signal Name Mode
1 DCD Data Carrier Detect Input
2 RD Receive Data Input
3 TD Transmit Data Output
4 DTR Data Terminal Ready Output
5 GND Ground
6 DSR Data Set Ready Input
7 RTS Request To Send Output
8 CTS Clear To Send Input
9 RI Ring Indicator Input
Please terminate any control signals that are not going to be used. The most common way to do
this is connect RTS to CTS and RI. Also, connect DCD to DTR and DSR. Terminating these pins, if
not used, will help insure you get the best performance from your adapter.

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ELECTRICAL SPECIFICATIONS,CONTINUED
RS-422 & RS-485 (DB9 Male)
Pin # Signal Name Mode
1 RX + Receive Data Positive Input
2 RX – Receive Data Negative Input
3 TX – Transmit Data Negative Output
4 TX + Transmit Data Positive Output
5 GND Ground
6 RTS + Request to Send Positive Output
7 RTS – Request to Send Negative Output
8 CTS – Clear to Send Negative Input
9 CTS + Clear to Send Positive Input

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Technical Specifications
Environmental Specifications
Specification Operating Storage
Temperature Range 0º to 70º C (32º to 158º F) -50º to 105º C (-58º to 221º F)
Humidity Range 10 to 90% R.H. Non-Condensing 10 to 90% R.H. Non-Condensing
Power Requirements
Supply line +5 VDC
Rating 500 mA
Manufacturing
All Sealevel Systems, Inc. printed circuit boards are built to UL 94V0 rating and are 100% electrically tested.
These printed circuit boards are solder mask over bare copper or solder mask over tin nickel.
Mean Time Between Failure (MTBF)
Greater than 150,000 hours (calculated).

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Hardware Configuration
Original Configuration
This 2403 ships from Sealevel Systems with the following configuration:
•RS-422 mode
•120 ohm termination
•1 K ohm pull up on RX+
•1 K ohm pull down on RX-
In order to change this configuration, the enclosure must be opened by removing the four screws located
on the bottom. When reassembling please note that the top and bottom halves of the enclosure are keyed
to fit in only one direction.
Electrical Interface Selection
Each of the four serial ports on the 2403 can be individually configured as an RS-232, RS-422, or RS-485
interface. This is selectable via the DIP switches and DIP shunts located on the circuit board (PCB). Each
of the switch positions is described on the following page.

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HARDWARE CONFIGURATION,CONTINUED
Switch Descriptions
Figure 1: Switches SW2 and SW4
LRS-485 option, OFF for RS-422.
OFF: No effect
ON : Connects TX+ to RX+ for two-wire operation
LRS-485 option, OFF for RS-422.
OFF: No effect
ON : Connects TX- to RX- for two-wire operation
TRS-422 and RS-485 option.
OFF: No effect
ON : Adds a 120 ohm termination resistor between RX+ and RX-
PU RS-485 option, OFF for RS-422.
OFF: No effect
ON : Adds a 1 K ohm pull-up resistor to RX+
PD RS-485 option, OFF for RS-422.
OFF: No effect
ON : Adds a 1 K ohm pull-down resistor to RX-
ON
1 2 3 4 5 6 7 8
OFF
910
Port 3
L
L
T
PU
PD
Port 4
L
L
T
PU
PD
SW2
Port 1
L
L
T
PU
PD
ON
1 2 3 4 5 6 7 8
OFF
910
Port 2
L
L
T
PU
PD
SW4

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HARDWARE INSTALLATION,CONTINUED
Switch Examples
Figure 2: RS-422/485 Interface Configuration
485 Mode Selection
OFF: RS-422 Mode
The transmitter lines TX+ and TX- are always driven
ON: RS-485 Mode
The transmitter lines TX+ and TX- are switched to high impedance when
the device is not actively transmitting data
NE RS-485 option, OFF for RS-422
OFF: The receiver is always enabled. In a two-wire setup the receiver will echo
back all transmitted data.
ON: The receiver is disabled when the transmitter is enabled. In a two-wire
setup the receiver will not echo back transmitted data.
Switch positions 1 and 2 are for port 1 and switch positions 3 and 4 for port 2 on SW3. Switch
positions 1 and 2 are for port 3 and switch positions 3 and 4 for port 4 on SW1.
ON
1 2 3 4
OFF
ON
1 2 3 4
OFF
485 3
NE 3
485 4
NE 4
485 1
NE 1
485 2
NE 2
SW1 SW3

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HARDWARE INSTALLATION,CONTINUED
Switch Examples Continued
Port 4 Port 3 Port 2 Port 1
Figure 3: Electrical Interface Configuration
Port 1: RS-232
This is not a valid configuration for the 2402.
The switches will have no effect.
Port 2: RS-485 two wire communication with no echo.
The corresponding shunt is in the 422/485 position.
Switches 485 2, NE 2, and Port 2 L, L, T, PU, and PD are all in the ON position.
Port 3: RS-422 with 120 ohm termination.
The corresponding shunt is in the 422/485 position.
Switches 485 3, NE 3, and Port 3 L, L, PU, and PD are all in the OFF position,
T is in the ON position.
Port 4: RS-485 two wire communication with echo.
The corresponding shunt is in the 422/485 position.
Switches 485 4, and Port 4 L, L, T, PU, and PD are all in the ON position,
NE 4 is in the OFF position.
RS 232 RS 232 RS 232 RS 232RS 422/485 RS 422/485 RS 422/485 RS 422/485
Port 3
L
L
T
PU
PD
ON
1 2 3 4 5 6 7 8
OFF
910
Port 4
L
L
T
PU
PD
ON
1 2 3 4 5 6 7 8
OFF
910
Port 1
L
L
T
PU
PD
Port 2
L
L
T
PU
PD
E1 E4E3E2 E5 E6 E7 E8
SW2 SW4
ON
1 2 3 4
OFF
ON
1 2 3 4
OFF
485 3
NE 3
485 4
NE 4
485 1
NE 1
485 2
NE 2
SW1 SW3

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Installation
Instructions For Software Installation Download
1. To obtain the most current software driver package from Sealevel’s website, download from here:
•SeaCOM for Windows
•SeaCOM for Linux
2. Click on the SeaCOM link in the ‘Downloads’ section to download the current driver.
3. Once downloaded, double-click on the executable to launch the InstallShield wizard and initiate
the driver installation.
4. SeaCOM software can also be downloaded from the 2403 product webpage:
https://www.sealevel.com/product/2403
SeaCOM Software Installation
To install Sealevel Systems software, you must log in as an administrator or have administrator
privileges in Windows.
For Windows XP and older versions of Windows, do not connect the device to a USB port until after
the software has been successfully installed. In Windows Vista and newer versions of Windows,
SeaCOM version 3.6.30 and later will install SeaCOM hardware that is already connected.
1. Locate the file on your computer (e.g., SS030703.exe), right-click on the filename, and click ‘Run as
Administrator’ in the fly-out menu.
2. When the ‘SeaCOM - InstallShield Wizard’ window appears, click the ‘Next’ button to initiate the
software installation.
3. When the ‘License Agreement’ window appears, accept the terms, and click ‘Next’ to continue. You
can click the ‘Print’ button to print out a copy of the agreement for your records. If you do not accept
the terms of the agreement, the installation will stop.

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INSTALLATION,CONTINUED
4. When the ‘Ready to Install the Program’ window appears, click the ‘Install’ button to install the
software. The files will be automatically installed into the ‘C:\Program Files (x86)’ folder on your
computer.
5. The setup file will automatically detect the operating environment and install the proper
components. Once the installation is complete, close the SeaCOM installer window.
6. You have completed the software driver installation process.
7. Refer to the Physical Installation section to connect and install your adapter.
Upgrading To The Current SeaCOM Driver
1. Download the current driver using the Instructions from the ‘Software Installation Download’
section above. Please take note of the destination directory to which it will save.
2. Uninstall the currently loaded SeaCOM software found in the ‘Apps and Features’ (Windows 10 or
newer) or ‘Programs and Features’ (Windows 8.1 and older) list.
3. Navigate to Device Manager and remove the 2403 by right clicking on the line items in ‘Universal
Serial Bus controllers’ and choosing ‘Uninstall’.
4. In the Device Manager under ‘Action,’ choose ‘Scan for Hardware changes. This will prompt the
installation of the adapter and associate it with the newly installed SeaCOM driver.
5. Proceed with the hardware installation of your SeaLINK USB serial adapter.

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INSTALLATION,CONTINUED
Hardware Installation
The 2403 can be connected to any Upstream Type A USB port at the PC host or an Upstream Hub. Since it
is hot-pluggable, there is no need to power down your computer prior to installation. Once you have installed
the software simply plug the USB connector into an available USB port. The drivers that were installed
during setup will automatically be used to configure the adapter.
Verifying Installation
To confirm that the serial ports have been successfully installed, look in Device Manager under ‘Ports (COM
& LPT).’ The COM assignments will be included with the associated COM numbers in parentheses.
To access Device Manager in Windows 10:
1. Right-click on the Start button (Windows logo).
2. In the fly-out menu, click ‘Device Manager.’
3. Continue with step 4 below.
To access Device Manager in Windows 7:
1. Right-click on ‘Computer’ in the Start menu.
2. Click ‘Manage’ in the fly-out menu to launch the ‘Computer Management’ console window.
3. In the left pane under ‘System Tools,’ click ‘Device Manager.’
4. In right pane near the bottom, expand the ‘Ports (COM & LPT)’ section by clicking the ‘>’ symbol.
5. You should now see the COM assignments with the associated COM numbers in parentheses.
Your system will assign the next available COM numbers, which will vary by computer (COM 3-6 as
shown in this example).

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INSTALLATION,CONTINUED
Uninstall & Upgrade Instructions
The SeaCOM software program adds entries to the system registry that are necessary for specifying the
operating parameters for your device. To completely remove the hardware and associated software, follow
the steps in the order that they appear.
To upgrade to the latest version of SeaCOM, follow the instructions to uninstall the hardware and software,
followed by the upgrade instructions.
Start with the hardware connected to a USB port. Do not unplug it until instructed to do so.
Remove Hardware Using Device Manager
To access Device Manager in Windows 10:
1. Right-click on the Start button.
2. In the fly-out menu, click ‘Device Manager.’
3. In Device Manager, open the ‘View’ menu and select ‘Show hidden devices.’
4. Continue with Step 4 below.

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INSTALLATION,CONTINUED
To access Device Manager in Windows 7:
1. Right-click on ‘Computer’ in the Start menu.
2. Click ‘Manage’ in the fly-out menu to launch the ‘Computer Management’ console window.
3. In the left pane under ‘System Tools,’ click ‘Device Manager.’
4. In right pane near the bottom, expand the ‘Universal Serial Bus controllers’ section by clicking the
‘>’ symbol.
5. Locate the SeaLINK device in the listing, highlighted below.
6. Right click on the entry for the SeaLINK device and click ‘Uninstall’ in the fly-out menu.